The present invention relates to a process which, by using prefabricated modules prefabricated at different manufacturing yards, from the assembly point, which is flooded, makes it possible to simplify, speed up and make a modular connection for use by road vehicles, and railway vehicles, pedestrians, an underwater crossing of water stretches.
The invention relates also to some specific outfits for practicing said process.
The process according to the invention essentially consists in butt-connecting, inside a flooded basin, large prefabricated modules, with a length on the order of 150 meters. These are introduced into the basin under free floating conditions, and are progressively pushed across beneath the stretch of water until the underwater crossing is complete.
From the prior art, different kinds of modular practicable crossings of water stretches are already known, which essentially consist of floating structures, or of structures laid on the water bed.
The structures of the first type have navigational drawbacks, and those of the second type are practically unrealizable beyond a certain depth and with irregular water beds. Also, in both cases, a yard always has to be established, which moves along the lay-out of the work, with inherent complications.
Modular processes are also known, which are carried out in a fixed yard inside a floodable basin, or situated on the bank adjacent to the basin, but these realizations also show considerable drawbacks.
Fixing a yard inside the basin wastes considerable time and money because the sequential steps of assemblage such as prefabrication of the module, ageing, or drying, of the same module, and dismantling the yard before launching the module, have to be repeated after each module is launched.
Fixing a yard on the bank, requires very powerful and expensive lifting means suitable for introducing into the floodable basin the prefabricated modules. Such modules consequently cannot be too large, and, furthermore, they require a long time to be built or to age or dry, during which time the operations of assemblage and launching are interrupted.